A system for controlling signals coming from or going to an aircraft simulator has a first slave circuit and a second slave circuit. The second slave circuit is used to monitor signals coming from the aircraft simulator. A multiplexer circuit is coupled to the first slave circuit. The first slave circuit sends control signals to the multiplexer circuit for controlling digital output signals being sent to the aircraft simulator. A master controller is coupled to the first slave circuit and the second slave circuit. The master controller is used for controlling operation of the first and second slave circuit. A computer system is coupled to the master controller. The computer system will display a listing of the aircraft simulator signals to be controlled. Selection of a desired aircraft simulator signal by an input device of the computer system will allow one to control the selected aircraft simulator signal.